I've had keyboard freezes for a month. Yesterday I had about 5 spontaneous reboots in the space of an hour, and this morning I discovered my shortcuts weren't working. I then had the great idea of removing one of my two keyboards and re-adding it, just to see what would happen. Ha, it didn't let me re-add. Something was obviously getting worse. So I made a backup copy of everything on my iPad Air in the iCloud and elsewhere and clicked the "delete account" button in the iCloud settings. I wasn't sure what to expect. Fortunately it didn't delete my world of data, it just removed it from the iPad. And when I relinked the iPad to my iCloud account, lo and behold all kinds of shortcuts I'd forgotten about appeared in the keyboard settings and my documents hadn't been deleted anywhere. I have the backup just in case. So... If there's a corrupt document I suppose it's still there, but so far so good. I know a lot of us have this problem, maybe this post will give someone some hope!